A heat transfer sheet comprises a substrate sheet and a heat transfer layer laminated on the substrate sheet and containing a dye which can be caused to migrate by heating to be transferred onto a transferable sheet, said heat transfer sheet containing a polyvinyl acetacetal resin as a binder component, the acetal moiety of said polyvinyl acetacetal resin being 50% by weight or more based on the total amount of the resin, and 80% by weight or more of said acetal moiety comprising polyvinyl acetacetal. A process for producing a polyvinyl acetacetal resin by the reaction of a polyvinyl alcohol and acetaldehyde in an aqueous phase in the presence of 4 to 10% by weight of an acid catalyst comprises initiating precipitation of an acetalated product by maintaining the reaction system at a temperature of 8 to 17 DEG C for 30 minutes or longer, and then maintaining said reaction at a temperature of 25 to 40 DEG C.
申请公布号
EP0271861(A2)
申请公布日期
1988.06.22
申请号
EP19870118521
申请日期
1987.12.14
申请人
DAI NIPPON INSATSU KABUSHIKI KAISHA;SEKISUI KAGAKU KOGYO KABUSHIKI KAISHA